helperExtractorFunction error using Monocular SLAM tutorial

Hi everyone,

I am trying to run the Monocular SLAM tutorial found here: https://www.mathworks.com/help/vision/examples/monocular-visual-simultaneous-localization-and-mapping.html. I am using Matlab2020a. I am getting the below error and I can't seem to figure out why. Any help would be appreciated.

Warning: Undefined custom extractor function 'helperExtractorFunction'. Please check if 'helperExtractorFunction' is on MATLAB's

search path.

> In bagOfFeatures/checkCustomExtractorOnLoad (line 1026)

In bagOfFeatures.loadobj (line 1373)

In SLAMTest (line 281)

Unrecognized function or variable 'helperExtractorFunction'.

Error in bagOfFeatures/invokeCustomExtractor (line 799)

[features, featureMetrics, varargout{1:nargout-2}] = extractor(img);

Error in bagOfFeatures>@(img)this.invokeCustomExtractor(img,params.CustomExtractor) (line 782)

this.Extractor = @(img)this.invokeCustomExtractor(img, params.CustomExtractor);

Error in bagOfFeatures/encodeSingleImage (line 591)

[descriptors,~,locations] = this.Extractor(img);

Error in bagOfFeatures/encodeScalarImageSet (line 571)

[features(j,:), words(j)] = this.encodeSingleImage(img, params);

Error in bagOfFeatures/encode (line 337)

this.encodeScalarImageSet(in, params);

Error in invertedImageIndex/addImages (line 200)

[wordHistograms, words] = this.BagOfFeatures.encode(imgSet, ...

Error in SLAMTest (line 303)

addImages(loopDatabase, currds, 'Verbose', false);

Answer 1

[Srivardhan Gadila]

I have heard that this issue is known and the concerned parties might fix it in an update or in a future release.

The workaround for this issue is changing the name of the helper function helperSURFFeatureExtractorFunction to helperExtractorFunction. Make sure you follow Syntax for Function Definition while renaming the function.